/**
 * @计算从5到50之间间隔为5的所有数字的三角形数
 *
 * @author	 wangshikun <wangshikun2010@gmail.com>
 * @copyright	(c) 2012 wangshikun <wangshikun2010@gmail.com>
 * @license	http://www.opensource.org/licenses/mit-license.php The MIT License
 * @package	default
 * @subpackage	default
 */

#include <stdio.h>
#include <cs50.h>
#include <stdlib.h>

int main(int argc, char *argv[]) {
	int s;

	for (int i=5; i<=50; i+=5) {
		s = i * (i + 1) / 2;
		printf("%2i行需要的*数是：%i\n", i, s);
	}
}
